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Abstract:

A multimedia data distribution system is provided. The multimedia data
distribution system comprises a multimedia controller and at least a
distribution zone. A distribution zone has a zone hub and zero to finite
number of zone media player. The zone hub receives multimedia data from a
multimedia content source through an out-of-zone data path and then
synchronously redistributes multimedia contents to rest of zone media
players via in-zone data paths. A multimedia controller utilizes
out-of-zone control path to transmit control message to a zone hub, which
in turn relays the control messages to addressed zone media player(s) via
in-zone control paths. The zone hub of a distribution zone receives
status updates from individual zone media players via in-zone status
update paths, aggregates them, and then relays to the multimedia
controller via the out-of-zone status update path. While out-of-zone
data, control, and status update paths are setting up based on Wi-Fi
connections to an infrastructure AP or a Hotspot, all of the in-zone
paths are established on Wi-Fi Direct peer-to-peer connections.

Claims:

1. A multimedia data distribution system, comprising: a multimedia
content source; a multimedia controller; and at least one distribution
zone, comprising: a zone hub, receiving multimedia data from the
multimedia content source through an out-of-zone data path; and at least
one zone media players, wherein each of the at least zone media player
directly receives the multimedia data from the zone hub through an
in-zone data path, wherein each of the in-zone data path is a wireless
peer-to-peer connection.

2. The multimedia data distribution system of claim 1, wherein the
multimedia controller is integrated with the zone hub in a portable
device.

3. The multimedia data distribution system of claim 1, wherein the
out-of-zone data path includes a Wi-Fi connection through an
infrastructure AP or a Wi-Fi Hotspot, or a Wi-Fi peer-to-peer device.

4. The multimedia data distribution system of claim 1, wherein each of
the in-zone data paths is a Wi-Fi Direct peer-to-peer connection.

5. The multimedia data distribution system of claim 1, wherein an
out-of-zone control path is established between the multimedia controller
and the zone hub and the out-of-zone control path includes a Wi-Fi
bidirectional data connection established through an infrastructure AP,
or a Wi-Fi Hotspot, or a Wi-Fi peer-to-peer device.

6. The multimedia data distribution system of claim 5, wherein an in-zone
control path is established directly between the zone hub and each of the
zone media players over the Wi-Fi Direct peer-to-peer connection, and
when a control message arrives at the zone hub via the out-of-zone
control path, the zone hub determines whether the control message is
destined to the zone hub itself or one of the zone media players or the
entire distribution zone, and the control message is terminated at the
zone hub as it is destined to the zone hub, or the control message is
relayed to the destined zone media player by the zone hub over the
corresponding in-zone control path as the control message is destined to
the zone media player, or the control message is relayed to each of the
zone media players or broadcasted to them altogether as the control
message is destined to the entire distribution zone.

7. The multimedia data distribution system of claim 1, wherein an
out-of-zone status update path is established between the multimedia
controller and the zone hub over a Wi-Fi data connection through an
infrastructure AP, or a Wi-Fi Hotspot, or a Wi-Fi peer-to-peer device.

8. The multimedia data distribution system of claim 7, wherein an in-zone
status update path is established between the zone hub and each of the
zone media players over the Wi-Fi Direct peer-to-peer connection, and the
zone hub aggregates status update messages respectively received from the
zone media players and relays to the multimedia controller periodically
via the out-of-zone status update path.

9. The multimedia data distribution system of claim 1, wherein a
plurality of direct control and status update paths are respectively
established between the multimedia controller and the zone hub and
between the multimedia controller and each of the zone media players and,
a control message and status update message are directly exchanged
between the multimedia controller and the zone hub or one of the zone
media players or the entire distribution zone through the corresponding
direct control and status update paths.

10. The multimedia data distribution system of claim 9, wherein each of
the control and status update paths includes a bidirectional
Bluetooth-low-energy connection.

11. The multimedia data distribution system of claim 1, wherein the at
least distribution zone comprises a first distribution zone and a second
distribution zone, and the multimedia controller is the zone hub of the
first distribution zone for relaying the multimedia data to the zone hub
of the second distribution zone.

12. The multimedia data distribution system of claim 1, wherein the
multimedia controller is a content source or is connected with the
content source through an infrastructure WiFi or wide area network (WAN)
connection.

13. A multimedia data distribution system, comprising: a portable device
having a multimedia controller and a zone hub, wherein the multimedia
controller is integrated with the zone hub in the portable device; and at
least a zone media player, wherein an in-zone data path is established
between the portable device and each of the zone media player, and each
of the zone media player directly receives multimedia data from the zone
hub in the portable device through the in-zone data path, wherein each of
the in-zone data path is a wireless peer-to-peer connection.

14. The multimedia data distribution system of claim 13, wherein an
in-zone control and status update path is established directly between
the zone hub and each of the zone media player.

15. The multimedia data distribution system of claim 14, wherein each of
the in-zone data, control and status update paths include the Wi-Fi
Direct peer-to-peer connection.

16. An operating method for a multimedia data distribution system,
wherein the data distribution system includes a multimedia content
source, a multimedia controller and at least one distribution zone, each
of the at least distribution zone has a zone hub and at least one zone
media player, an in-zone data path is established between the zone hub
and each of the zone media player, and an out-of-zone data path is
established between the multimedia controller and the zone hub of each of
the at least distribution zone, the operating method comprising: a
multimedia data transmission operation including receiving multimedia
data by the zone hub through the out-of-zone data path and directly
redistributing the received multimedia data by the zone hub to each of
the zone media player through the corresponding in-zone data path,
wherein each of the in-zone data path is a wireless peer-to-peer
connection.

17. The operating method of claim 16, wherein the out-of-zone data path
includes a Wi-Fi connection through an infrastructure AP or a Wi-Fi
Hotspot, or a Wi-Fi peer-to-peer device.

18. The operating method of claim 16, wherein an out-of-zone control path
is established between the multimedia controller and the zone hub, an
in-zone control path is established directly between the zone hub and
each of the zone media players over the Wi-Fi Direct peer-to-peer
connection, and the operating method further comprises a control message
transmission operation comprising: determining by the zone hub whether a
control message is destined to the zone hub itself or one of the zone
media players or the entire distribution zone when the control message
arrives at the zone hub via the out-of-zone control path; terminating the
control message at the zone hub when the control message is destined to
the zone hub; relaying the control message by the zone hub to the
destined zone media player over the corresponding in-zone control path
when the control message is destined to the zone media player; and
relaying or broadcasting the control message by the zone hub to each of
the zone media players when the control message is destined to the entire
distribution zone.

19. The operating method of claim 18, wherein the out-of-zone control
path includes a Wi-Fi bidirectional data connection established through
an infrastructure AP, or a Wi-Fi Hotspot, or a Wi-Fi peer-to-peer device.

20. The operating method of claim 16, wherein an out-of-zone status
update path is established between the multimedia controller and the zone
hub over a Wi-Fi data connection through an infrastructure AP, or a Wi-Fi
Hotspot, or a Wi-Fi peer-to-peer device, an in-zone status update path is
established between the zone hub and each of the zone media players over
the WiFi Direct peer-to-peer connection, and the operating method further
comprises a status updating operation comprises: aggregating status
update messages respectively from the zone media players by the zone hub;
relaying the status update messages to the multimedia controller
periodically via the out-of-zone status update path.

21. The operating method of claim 16, wherein a plurality of direct
control and status update paths are respectively established between the
multimedia controller and the zone hub and between the multimedia
controller and each of the zone media players, and the operating method
further comprises a control message transmission operation comprising:
directly exchanging a control message and the status update message
between the multimedia controller and the zone hub or one of the zone
media players or the entire distribution zone through the corresponding
direct control and status update paths.

22. The operating method of claim 21, wherein each of the control and
status update paths includes a bidirectional Bluetooth-low-energy
connections.

23. The operating method of claim 21, further comprising a
status-updating operation, wherein the status updating operation
comprises: sending a status update message by each of the zone media
players to the multimedia controller through the corresponding status
update path.

24. The operating method of claim 16, further comprising a discovery
operation, wherein the discovery operation comprises: sending probe
requests by the multimedia controller on a plurality of Wi-Fi channels;
and sending a probe response by each of the zone media players to the
multimedia controller in response to the probe requests received by each
of the zone media players.

25. The operating method of claim 16, further comprising a discovery
operation, wherein the discovery operation comprises: periodically
sending undirected Bluetooth-low-energy advertisements by each of the
zone hub and the zone media players on a plurality of predetermined
advertisement channels; and scanning the predetermined advertisement
channels by the multimedia controller for the undirected
Bluetooth-low-energy advertisements.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority benefit of U.S. provisional
application Ser. No. 61/605,728, filed on Mar. 1, 2012. The entirety of
the above-mentioned patent application is hereby incorporated by
reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

[0002] 1. Field of Invention

[0003] The present invention relates to a wireless multimedia data
distribution system and an operating method of the distribution system.
More particularly, the present invention relates to a multimedia data
distribution system and an operating method of the multimedia data
distribution system.

[0004] 2. Description of Related Art

[0005] Wireless Fidelity (Wi-Fi) is a popular wireless networking
technology that allows electronic devices to exchange data wirelessly
(using radio waves) through either an infrastructure Access Point (AP) or
peer-to-peer connections over a local area network while enabling
high-speed Internet connections. In an infrastructure AP based Wi-Fi
multimedia data distribution system, all multimedia devices must be
connected to an infrastructure AP. The source device first transmits
multimedia contents to the infrastructure AP it is associated with, and
the infrastructure AP in turn redirects the multimedia content to the
intended destination device(s).

[0006] Therefore, for a conventional Wi-Fi data distribution system to
operate, each of the devices needs to have a public IP address and a
Wi-Fi infrastructure AP must be presented in the system. In other words,
a Wi-Fi infrastructure AP based multimedia data distribution system will
not be able to function when Wi-Fi infrastructure AP is absent.

SUMMARY OF THE INVENTION

[0007] The present invention describes a general-purpose multimedia data
distribution system and an operating method of the multimedia data
distribution system that enables multimedia data transmission, control
message transmission, and status update message transmission independent
from the existence of a Wi-Fi infrastructure AP. The architecture,
configuration, and operation method of the general multimedia data
distribution system are applicable to the specific enablement of a
Wireless Multi-Room Audio (WMRA) distribution system.

[0008] The present invention provides a multimedia data distribution
system. The multimedia data distribution system comprises content source,
a multimedia controller, and at least one distribution zone. A
distribution zone, which is a logical cluster of Wi-Fi device(s), has one
device known as the zone hub and zero to finite number of non-zone-hub
devices known as the zone media players. The zone hub receives multimedia
data from a multimedia content source, which can be the multimedia
controller itself or an Internet media source, through an out-of-zone
data path. The zone hub then redistributes multimedia data synchronously
or asynchronously to all the zone media players in its distribution zone
through in-zone data path(s). The out-of-zone data path can be a Wi-Fi
connection to an infrastructure AP, or a Hotspot, or a peer device while
each of the in-zone data paths is a Wi-Fi Direct peer-to-peer connection.
The multimedia controller controls distribution zone operations and
receives distribution zone status updates via control and status update
paths, respectively. Control and status update paths are both established
based on some type of Wi-Fi connections.

[0009] The invention further provides a method to implement control and
status update paths based on Bluetooth Low Energy (BLE). In one
embodiment, the multimedia controller establishes BLE data channel
connections with the zone hub and each of the zone media players. The
control and status update messages are sent directly between the
multimedia controller and the zone hub/zone media players. In another
embodiment, both control and status update paths are established using
directed or undirected BLE advertisement broadcasts.

[0010] The invention also provides a configuration of the multimedia data
distribution system that comprises a multifunctional central device (MCD)
and at least one zone media player. This multimedia distribution system
is centered on the MCD device having the combined functionalities of a
multimedia controller, a multimedia content source, and a zone hub. An
in-zone data path, which is a Wi-Fi Direct peer-to-peer connection, is
established between the zone hub and each of the zone media players. The
in-zone control and status update paths are also based on Wi-Fi Direct
peer-to-peer connections between the zone hub and individual zone media
player(s). The zone hub relay control messages to each of the zone media
players and status update messages back to the multimedia controller. The
out-of-zone data, control, and status update paths are internal to the
MCD. The MCD provides Internet connectivity to the distribution zone via
infrastructure AP or wide area network (WAN) connections.

[0011] In the present invention, the multimedia data transmission, the
control message transmission, the status update operation and the
discovery operation of the multimedia data distribution system are
operated in absence of an infrastructure access point. Further, the
connections for transmitting signals between the controller, the zone hub
and the zone media players may be established in different ways based on
network topology and device capabilities.

[0012] It is to be understood that both the foregoing general description
and the following detailed description are exemplary, and are intended to
provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and constitute a
part of this specification. The drawings illustrate embodiments of the
invention and, together with the description, serve to explain the
principles of the invention.

[0014]FIG. 1 is a schematic diagram showing a multimedia data
distribution system according to one embodiment of the present invention.

[0015]FIG. 2 is a flow chart illustrating multimedia data transmission
operation of a distribution zone according to one embodiment of the
present invention.

[0016] FIG. 3 is a schematic diagram showing data paths, control paths,
and status update paths of a multimedia data distribution system
according to one embodiment of the present invention.

[0017]FIG. 4 is a flow chart illustrating a control message transmission
operation of the multimedia data distribution system with the control
paths shown in FIG. 3 according to one embodiment of the present
invention.

[0018]FIG. 5 is a flow chart illustrating a status updating operation of
the multimedia data distribution system with the status update paths
shown in FIG. 3 according to one embodiment of the present invention.

[0019] FIG. 6 is a schematic diagram showing control paths and data paths
of a multimedia data distribution system according to another embodiment
of the present invention.

[0020]FIG. 7 is a flow chart illustrating a control message transmission
operation of the multimedia data distribution system with the control and
status update paths shown in FIG. 6 according to one embodiment of the
present invention.

[0021]FIG. 8 is a flow chart illustrating a status updating operation of
the multimedia data distribution system with the control and status
update paths shown in FIG. 6 according to one embodiment of the present
invention.

[0022]FIG. 9 is a flow chart illustrating a discovery operation of the
multimedia data distribution system according to one embodiment of the
present invention.

[0023]FIG. 10 is a flow chart illustrating a discovery operation of the
multimedia data distribution system according to another embodiment of
the present invention.

[0024] FIG. 11 is a schematic diagram showing a multimedia data
distribution system according to another embodiment of the present
invention.

[0025]FIG. 12 presents a variation to the multimedia data zone system
topology in FIG. 11 according to the other embodiment of the present
invention.

[0026] FIG. 13 is a schematic diagram showing a multimedia data
distribution system according to the other embodiment of the present
invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] A multimedia data distribution system, such as a wireless
multi-room audio (WMRA) system, comprises a content source, a multimedia
controller, and at least one distribution zone (a.k.a. speaker zone or
music zone in WMRA system). A distribution zone is usually created by a
user using the multimedia controller and consists of one zone hub (a.k.a.
zone master in WMRA system) and zero to finite number of zone media
players (a.k.a. zone slaves in WMRA system). The structure of a
distribution zone closely resembles the star networking topology, in
which the zone hub acts as the central node of the subnet. The zone hub
connects to a content source, which may be the multimedia controller
itself or a content server residing in the Internet, via Wi-Fi connection
with an infrastructure AP, a Wi-Fi Hotspot, or a Wi-Fi peer device. When
in operation, the zone hub receives music content from a user selected
content source and synchronously redistributes to all zone media players
in the distribution zone over Wi-Fi Direct peer-to-peer connections. A
specialized media controller or a display-capable computing device, such
as smartphone, tablet, or laptop computer, is used to control the
formation and operation of a distribution zone. The media controller
asserts control over an entire distribution zone or individual zone media
players by sending control messages over the in-zone control path to the
zone hub, which in turn relays to individual zone media players via
in-zone control paths. Zone hub receives status update messages from
individual zone media players inside the distribution zone via in-zone
status update paths and relays aggregated status update messages to the
multimedia controller via out-of-zone status update path. The out-of-zone
data, control, and status updates paths are established over Wi-Fi
connections to an infrastructure AP, or a Hotspot, or a peer-to-peer
device. The in-zone data, control, and status update paths are all based
on Wi-Fi Direct peer-to-peer connections.

[0028]FIG. 1 is a schematic diagram showing a multimedia data
distribution system according to one embodiment of the present invention.
As shown in FIG. 1, the multimedia data distribution system 100 comprises
a multimedia controller 102 and at least one distribution zone 104.
Noticeably, the multimedia controller 102 controls the formation,
operation, and dissolution of individual distribution zones. Moreover,
the multimedia controller 102 can be, for example, a display-capable
portable device in any shape or form factor, such as smartphone, tablet,
or laptop computer. Also, the multimedia controller 102 can be, for
example, a content source providing various kinds of multimedia data
(such as audio data, video data and audio-video data) and having ability
of controlling multimedia data. Alternatively, the multimedia controller
102, for example, can be connected with the content source (such as a
cloud server 120 shown in FIG. 1) through an infrastructure Wi-Fi
connection or a wide area network (WAN) connection.

[0029] Furthermore, in each of the distribution zones 104 of the
multimedia data distribution system 100, there is a zone hub 106 and zero
to finite number of zone media players 108 (such as the zone media
players 108a and 108b). A distribution zone 104 operates as a Wi-Fi
Direct peer-to-peer group with the zone hub 106 acting as the P2P Group
Owner (GO). The zone hub 106 can be, for example, a speaker, a display
device, a multimedia player or a portable device (including smart phone,
a personal digital assistant, a tablet PC or a laptop) or any electronic
device supporting the Wi-Fi Direct peer-to-peer function. Further, each
of the zone media players 108 can be, for example, a speaker, a display
device, a multimedia player or a portable device (including smart phone,
a personal digital assistant, a tablet PC and a laptop) or any electronic
device supporting the Wi-Fi Direct peer-to-peer function. In the present
embodiment shown in FIG. 1, there are two zone media players 108a and
108b in the distribution zone 104. However, the number of the zone media
players 108 in the distribution zone 104 does not limit the scope of the
present invention.

[0030] Moreover, as shown in FIG. 1, an out-of-zone data path 110 is
established between the zone hub 106 and the multimedia controller 102.
The out-of-zone data path 110 can be, for example, a Wi-Fi connection
through an infrastructure AP, or Wi-Fi Hotspot, or a Wi-Fi peer-to-peer
device (such as Wi-Fi Direct or Wi-Fi IBSS). Also, in-zone data paths are
established between the zone hub 106 and each of the zone media players
108. For instance, the in-zone data path 112a is established between the
zone hub 106 and the zone media player 108a and the in-zone data path
112b is established between the zone hub 106 and the zone media player
108b. It should be noticed that each of the in-zone data paths 112a and
112b is a Wi-Fi Direct peer-to-peer connection. That is, according to the
Wi-Fi Direct spec, a pair of electronic devices with Wi-Fi peer-to-peer
connection can directly transfer data between each other.

[0031]FIG. 2 is a flow chart illustrating multimedia data transmission
operation of a distribution zone according to one embodiment of the
present invention. In multimedia data distribution system 100 as
illustrated in FIG. 1, the zone hub 106 receives multimedia data sent
from a multimedia content source, which can be the multimedia controller
102 or an Internet media source, through the out-of-zone data path 110
(the step S201) and synchronously re-distribute the received multimedia
data to all the zone media players 108a and 108b through in-zone data
paths 112a and 112b respectively (the step S205).

[0032] In the proceeding embodiment, the topology of the multimedia data
distribution system 100, the multimedia data transmission connections
(including the data paths between the multimedia controller 102 and the
zone hub 106 and between the zone hub 106 and each of the zone media
players 108) and the multimedia data transmission operation of the
multimedia data distribution system 100 are described. In the subsequent
embodiments, the control and status update message transmission
connections of the multimedia data distribution system 100, the control
message transmission operation and the status updating operation of the
multimedia data distribution system 100 are further illustrated with
Figures.

[0033] FIG. 3 is a schematic diagram showing data paths, control paths,
and status update paths of a multimedia data distribution system
according to one embodiment of the present invention. The thick dashed
line 332 represents the out-of-zone data path that connects a content
source to a zone hub. The thick solid lines 334a and 334b represent the
in-zone data paths between the zone hub 306 and zone media player 308a
and 308b, respectively.

[0034] The thin solid line 322 represent out-of-zone control path from
multimedia controller 302 to the zone hub 306 and the pair of thin solid
lines 324a and 324b represent in-zone control paths between zone hub 306
and each of the zone media player 308a and 308b, respectively. Further,
the out-of-zone control path 322 can be, for example, a Wi-Fi
bidirectional data connection established through an infrastructure AP,
or a Wi-Fi Hotspot, or a Wi-Fi peer-to-peer device. In practice, the
control message can be delivered to the zone hub 306 using Wi-Fi MAC
(Medium Access Control) protocol or higher layer protocols such as TCP/IP
(Transport-Control-Protocol/Internet-Protocol). In contrast, in-zone
control paths 324a and 324b are established directly between the zone hub
306 and respective zone media players 308a and 308b over Wi-Fi Direct
peer-to-peer connections. When a control message arrives at the zone hub
306 via the out-of-zone control path 322, the zone hub 306 first
determines whether the control message is destined to itself, or a
specific zone media player, or the entire distribution zone. A control
message destined to the zone hub will be terminated at the zone hub 306.
A control message destined to a specific zone media player will be
relayed to the zone media player by the zone hub 306 over in-zone control
path 324a or 324b. A control message destine to the entire distribution
zone can either be relayed to each zone media player individually or
broadcasted to them altogether.

[0035] In addition, the thin dashed lines 328a and 328b represent in-zone
status update paths running respectively from zone media player 308a and
308b to zone hub 306 while the thin dashed line 326 is representing the
out-of-zone status update path from zone hub 306 back to the multimedia
controller 302. Moreover, each of the in-zone status update paths 328a
and 328b is respectively established between the zone hub 306 and each of
the zone media players 308a and 308b over Wi-Fi Direct peer-to-peer
connections. The zone hub 306 aggregates status update messages received
from individual zone media players 308a and 308b and relays to the
multimedia controller 302 periodically via the out-of-zone status update
path 326. Further, the out-of-zone status update path 326 is established
between the zone hub 306 and the multimedia controller 302 over a Wi-Fi
data connection through an infrastructure AP, or a Wi-Fi Hotspot, or a
Wi-Fi peer-to-peer device as previously mentioned. In practice, the
status update message from the zone hub 306 can be delivered to the
multimedia controller 302 using, for example, Wi-Fi MAC (Medium Access
Control) protocol or higher layer protocols such as TCP/IP
(Transport-Control-Protocol/Internet-Protocol).

[0036] It should be noticed that, the multimedia data distribution system
as shown in FIG. 3 could have many variations in actual implementation.
In one embodiment, the out-of-zone data path 332 may have to be routed
through the multimedia controller in case an infrastructure AP is absent.
In another embodiment, the content source 330 and the multimedia
controller 302 may collocate in the same physical entity. In yet another
embodiment, the content source 330, the multimedia controller 302, and
the zone hub 306 can all be integrated into a single physical device of
any shape and form factor. More clearly, the functionalities of a
multimedia controller 302, a content source 330, and a zone hub 306 may
be carried out by separate entities of distinct functionalities or by an
integrated entity capable of performing multiple roles at the same time.
In the present embodiment shown in FIG. 3, the out-of-zone data path 332,
the out-of-zone control path 322, and the out-of-zone status update path
326 are all based on Wi-Fi connection(s) to either an infrastructure AP
or a Hotspot. Meanwhile, the in-zone data paths 334a/334b, the in-zone
control paths 324a/324b, and the in-zone status update paths 328a/328b
are all based on Wi-Fi Direct peer-to-peer connections. This networking
model requires zone hub 306 to engage in concurrent STA/GO (Station/Group
Owner) operation.

[0037]FIG. 4 is a flow chart illustrating a control message transmission
operation of the multimedia data distribution system with the control
paths shown in FIG. 3 according to one embodiment of the present
invention. When a control message (such as the control message for tuning
down the volume of one of the zone media players 308) arrives at the zone
hub 306 from the multimedia controller 302 through the out-of-zone
control path 322 (the step S401), the zone hub 306 will timely relay the
message to addressed zone media player 308a or 308b through in-zone
control path 324a or 324b (the step S405).

[0038]FIG. 5 is a flow chart illustrating a status updating operation of
the multimedia data distribution system with the status update paths
shown in FIG. 3 according to one embodiment of the present invention. In
the step S501, the zone media player 308a and 308b each sends status
update messages to the zone hub 306 via respective in-zone status update
path 328a and 328b. In the step S505, the zone hub 306 aggregates status
update messages received from individual zone media players (308a and
308b) and relay to the multimedia controller 302 via out-of-zone status
update path 326.

[0039] FIG. 6 is a schematic diagram showing control paths and status
update paths of a multimedia data distribution system according to
another embodiment of the present invention. As shown in FIG. 6, dotted
lines 622, 626a, and 626b represent the control and status update paths
that run from the multimedia controller 602 directly to the zone hub 606,
the zone media player 608a, and the zone media player 608b, respectively.
In other words, there is a direct control and status update path between
multimedia controller 602 and each of the nodes (606, 608a, and 608b) in
the distribution zone. In contrast to the control and status update
scheme shown in FIG. 3, the control and status update scheme illustrated
in FIG. 6 do not require the zone hub 606 to relay control messages and
status update messages between multimedia controller 602 and zone media
players 608a and 608b.

[0040] In one embodiment, the control and status update paths 622, 626a,
and 626b are all based on bidirectional Bluetooth Low Energy (BLE) data
channel connections. In this embodiment, the multimedia controller 602
establishes BLE data channel connections with the zone hub 606 and each
of the zone media players 608a and 608b. Further, the control messages
and status update messages are sent directly between the multimedia
controller 602 and the zone hub 606/zone media players 608a and 608b
without being relayed through the zone hub 606. More clearly, the control
messages and status update messages are encoded in the payloads of BLE
data channel PDU (Protocol Data Unit) packets. The multimedia controller
602 is the Master of all the BLE data channel connections while zone hub
606 and zone media players 608a and 608b are the slaves of their
respective connections. The multimedia controller 602 determines the
connection event interval for each of the BLE data channel connections.
During each connection event, the master (multimedia controller 602) will
first transmit a data channel PDU to the slave, which may carry a control
message or be Null if there is no control message to be sent. The slave,
upon receiving the data channel PDU from the master, will in turn
transmits a data channel PDU back to the master, which may carry status
update message or be Null if no status update is available. According to
another embodiment, the control and status update paths may all be based
on directed or undirected BLE advertisement broadcasts.

[0041]FIG. 7 is a flow chart illustrating a control message transmission
operation of the multimedia data distribution system with the control and
status update paths shown in FIG. 6 according to one embodiment of the
present invention. When the multimedia controller 602 needs to send a
control message (such as the control message for tuning down the volume
of the zone media players 608a) to the zone media player 608a, the
control message is sent directly through control path 626a (the step
S701).

[0042]FIG. 8 is a flow chart illustrating a status updating operation of
the multimedia data distribution system with the status update paths
shown in FIG. 6 according to one embodiment of the present invention. As
shown in FIG. 8, in the status updating operation, each of the zone media
players 608a and 608b directly sends the status update message to the
multimedia controller 602 through direct status update paths 626a and
626b, respectively (S801).

[0043] Besides the multimedia data transmission operation, the control
message transmission operation and the status updating operation, the
operating method of the multimedia data distribution system of the
present invention further comprises a discovery operation. FIG. 9 is a
flow chart illustrating a discovery operation of the multimedia data
distribution system according to one embodiment of the present invention.
The discovery operation of a multimedia controller closely resembles the
Wi-Fi Direct discovery procedures. The behaviors of wireless media
players during discovery, however, depend on whether the media player is
associated with a zone hub in a distribution zone. In order to speed up
the discovery, wireless media players that have not associated with any
distribution zone will only passively await incoming probe requests on
one of the Wi-Fi Direct social channels instead of performing their own
active scans. The wireless media players that have associated with a
distribution zone and thereby became zone media player will neither
listen nor respond to incoming probe requests according to the Wi-Fi
Direct spec. Instead, the corresponding zone hub will respond to probe
requests on their behalves. As shown in FIG. 9, in the discovery
operation of the present embodiment, the multimedia controller sends a
series of probe requests on a plurality of Wi-Fi channels (the step
S901), including channel 1, channel 6 and channel 11, for example.
Further, the probe requests can carry proprietary information of the
multimedia controller, which includes unique and user-friendly controller
name, or Wi-Fi capability, or other specific information about the
intended multimedia data distribution system. At the time the multimedia
controller sends probe requests on the predetermined listen channels,
wireless media players not associated with any distribution zone
passively await the probe requests on one of the predetermined listen
channels and respond with a probe response upon reception of a probe
request (the step S905). The probe response can also carry proprietary
information about the responding media player. Moreover, the probe
responses sent from a zone hub will also contain specifics about the zone
media players current associated with zone hub.

[0044]FIG. 10 is a flow chart illustrating a discovery operation of the
multimedia data distribution system according to another embodiment of
the present invention. The discovery operation of the present embodiment
closely resembles the BLE advertisement mechanism. Each wireless speaker
periodically transmits BLE advertisement packets over a plurality of
predefined BLE advertisement channels. The multimedia controller, in
searching for wireless zone media players, listens to incoming BLE
advertisement packets on the BLE advertisement channels. As shown in FIG.
10, according to the BLE advertisement mechanism, in the discovery
operation of the present embodiment, each of the zone hubs and zone media
players periodically sends undirected BLE advertisement packets on a
plurality of predetermined BLE advertisement channels (the step S1001).
The predetermined BLE advertisement channels include channel 37, channel
38 and channel 39, for example. Furthermore, the undirected BLE
advertisement packet can, for example, carry the proprietary information
of the corresponding zone hub and zone media player, which may include
unique and user-friendly player name and/or other information relevant to
the advertising device. In the step S1005, the multimedia controller, in
searching for wireless zone media players, listens to the BLE
advertisement packets on all of the predetermined BLE advertisement
channels and decodes proprietary information carried in the corresponding
undirected BLE advertisement packets.

[0045] Taking Wireless Multi-Room Audio (WMRA) distribution system as an
exemplary embodiment, the WMRA system comprises a content source, a media
controller (i.e. multimedia controller) and at least one speaker zone
(i.e. the distribution zone), each of which is made of one zone hub and
zero to finite number of zone speakers (i.e. zone media player). Outside
the speaker zones, the media controller establishes and maintains
out-of-zone data, control, and status update paths with each of the zone
hubs. Inside each speaker zone, the zone hub establishes and maintains
in-zone data, control, and status update paths with each of the zone
speakers. The operation of a WMRA speaker zone comprises steps of
receiving musical content by the zone hub from a content source through
the out-of-zone data path and synchronously redistribute to each of the
zone speakers through corresponding in-zone data paths. The operation of
a WMRA zone hub also comprises steps of relaying control messages
received from the media controller over the out-of-zone control path to
individual zone speakers over the in-zone control paths. The operation of
a WMRA zone hub further comprises steps of relaying status update
messages received from individual zone speakers over in-zone status
update paths to the media controller over out-of-zone status update path.

[0046] In the previous embodiment shown in FIG. 1, there is one
distribution zone 104 in the multimedia data distribution system 100.
However, the number of the distribution zone 104 in a multimedia data
distribution system 100 does not limit the scope of the present
invention. FIG. 11 is a schematic diagram showing a multimedia data
distribution system according to one embodiment of the present invention.
In the embodiment shown in FIG. 11, a multimedia controller 1102 can
control more than one distribution zones (such as the distribution zones
1104a and 1104b) even though the connection topologies of these
distribution zones are different from each other. That is, the connection
topology (such as the Wi-Fi Direct peer-to-peer connection, the
infrastructure Wi-Fi connection or the Bluetooth-low-energy connection)
of the distribution zone 1104a may be different from that of the
distribution zone 1104b. However, they all can connect to the same
multimedia controller 1102.

[0047] In the previous embodiments shown in FIG. 1 and FIG. 11, a
multimedia controller not only can control one or more distribution zones
but may also be the content source of one or more distribution zones.
However, the functions of the multimedia controller are not limited
thereto. FIG. 12 presents a variation to the multimedia data zone system
topology in FIG. 11 according to the other embodiment of the present
invention. As shown in FIG. 12, there are a first distribution zone 1204a
and a second distribution zone 1204b in the multimedia data distribution
system 1200. Multimedia controller 1202, which is the controller of both
of the first distribution zone 1204a and the second distribution zone
1204b, is also the zone hub 1206a of the first distribution zone 1204a.
More specifically, multimedia controller 1202 assumes the functionalities
of multimedia controller, zone hub, and content source in the first
distribution zone 1204a while concurrently controlling and bridging
content source to the second distribution zone 1204b.

[0048] FIG. 13 is a schematic diagram showing a multimedia data
distribution system according to the other embodiment of the present
invention. As shown in FIG. 13, in the present embodiment, the multimedia
data distribution system 1300 comprises a multifunctional central device
(MCD) 1302. The MCD 1302 has the combined functionalities of a multimedia
controller, a multimedia content source, and a zone hub. Furthermore, the
MCD 1302 can be, for example, a portable device such as a smart phone, a
personal digital assistant, a tablet PC, or a laptop. More clearly, this
multimedia distribution system is centered on the MCD 1302. The
multimedia data distribution system 1300 of the present embodiment
further comprises at least one zone media player (in the present
embodiment, there are two zone media players 1308a and 1308b). Moreover,
the MCD 1302 can have, for example, a multimedia controller 1302a and a
zone hub 1302b built therein. In other words, the multimedia controller
1302a is integrated with the zone hub 1302b in the MCD 1302. An in-zone
data path (labeled as 1312a and 1312b respectively), which is a Wi-Fi
Direct peer-to-peer connection, is established between the zone hub 1302b
and each of the zone media players 1308a and 1308b. The in-zone control
and status update paths (labeled as 1324a and 1324b respectively) are
also based on Wi-Fi Direct peer-to-peer connections between the zone hub
1302b and individual zone media player(s). The zone hub 1302b will relay
control messages to each of the zone media players 1308a and 1308b and
status update messages back to the multimedia controller 1302a. The
out-of-zone data, control, and status update paths between the zone hub
1302b and the multimedia controller 1302a are all internal to the MCD and
function the same way as they do in discrete implementations. The MCD
provides Internet connectivity to the distribution zone via
infrastructure AP or wide area network (WAN) connections.

[0049] In one embodiment, the multimedia data distribution system having
the MCD can be, for example, configured to comprise a first distribution
zone and a second distribution zone. That is, there are more than one
distribution zones within one multimedia data distribution system having
the MCD. In this multimedia distribution system, the MCD plays multiple
roles. For the first distribution zone, the MCD is the multimedia
controller and Wi-Fi Hotspot that provides Internet connectivity to the
zone hub. For the second distribution zone, the MCD functions as
mentioned in the previous embodiment shown in FIG. 13.

[0050] In the embodiment shown in FIG. 13, the MCD has the combined
functionalities of a multimedia controller, a multimedia content source,
and a zone hub. However, the present invention is not limited by the
functionalities of the MCD. In another embodiment of the present
invention, the multimedia controller of the MCD maybe a local content
source or is connected with the content source through an infrastructure
Wi-Fi connection or wide area network (WAN) connection.

[0051] In the present invention, the multimedia data transmission, the
control message transmission, the status update message transmission, and
the discovery operation of the multimedia data distribution system remain
fully functional in absence of the infrastructure access point. Further,
the connections for transmitting signals between the controller, the zone
hub and the zone media players may be established in different ways based
on network topology and device capabilities.

[0052] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the present
invention without departing from the scope or spirit of the invention. In
view of the foregoing descriptions, it is intended that the present
invention also cover modifications and variations of this invention if
they fall within the scope of the following claims and their equivalents.